[2 days left] What’s wrong with your cloud strategy? Learn why multicloud solutions matter with Nimble Storage.Register Now

x
?
Solved

Getting server name/time

Posted on 1998-06-17
5
Medium Priority
?
615 Views
Last Modified: 2010-04-04
I have function that gets the time from the server using net from the command line. I would like something that works in Windows 95 and NT, in NT it seems one can use NetRemoteTOD/Timeserv in the resource kit, should I implement this if NT is running or should I stick with net?

Anyone, the function used to work, but in porting to 32-bit I have now a problem getting the server name, my code is as follows:

function GetServerName(var serverName: string): boolean;
var
   x: integer;
   fullNetPath, driveLetter: string;
   slstDrives: TStringList;
   returnValue: word;
   i: integer;

   function TrimNetPath: string;
   var
     lengthStringToTrim: word;
     i : integer;
     nextChar, netPathToTrim: string;
   begin
      { the fully qualified network path is in the form
        \\serverName\networkPath (stored in fullNetPath)
        this function returns the server name }
      netPathToTrim := fullNetPath;
      lengthStringToTrim := Length(netPathToTrim);
      i := 3;
      Result := '\\';
      nextChar := Copy(netPathToTrim, i, 1);
      while ((nextChar <> '\') and (i <= lengthStringToTrim)) do begin
         Result := Result + nextChar;
         Inc(i);
         nextChar := Copy(netPathToTrim, i, 1)
      end;
   end;
begin
   { initialize variables }
   x := 256;

   { get DRIVE_REMOTE letters }
   slstDrives := TStringList.Create;
   try
      // other function of mine that returns remote drive letters
      GetDriveLettersForDriveType([DRIVE_REMOTE], slstDrives);
      i := -1;
      if slstDrives.Count > 0 then
         repeat
            inc(i);
            { get fully qualified network path - API call }
            driveLetter := Format('%s:', [Copy(slstDrives.Strings[i], 1, 1)]);
            returnValue := WNetGetconnection(PChar(driveLetter), PChar(fullNetPath), x);
         until ((returnValue = WN_SUCCESS) or (i = slstDrives.Count - 1));
   finally
      slstDrives.Free;
   end;

   Result := (returnValue = WN_SUCCESS);
   if result then
      serverName := TrimNetPath
   else
      serverName := '';
end;

The problem is with WNetGetconnection, the return value I get for say my f drive (driveLetter = f:) is 487, which is none of the errors defined (GetLastError returns the same). Can anyone see what I might be doing wrong? Or perhaps suggest an alternative?

Thanks, Tom.

0
Comment
Question by:tomcorcoran
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2
5 Comments
 
LVL 3

Accepted Solution

by:
vladika earned 200 total points
ID: 1353672
ErrorCode 487 is ERROR_INVALID_ADDRESS.
You must allocate enough space for fullNetPath
Try
X := 0;
WNetGetconnection(PChar(driveLetter), '', x);
SetString(fullNetPath, nil, X);
 returnValue := WNetGetconnection(PChar(driveLetter), PChar(fullNetPath), x);
0
 

Author Comment

by:tomcorcoran
ID: 1353673
Vladika,

Thanks a lot, that worked great. Is the only way to alocate space for fullNetPath to run WNetGetConnection twice?

I also want this function to work for 16-bit, currently I have:

            {$IFDEF WIN32}
            // allocate space for fullNetPath
            WNetGetconnection(PChar(driveLetter), '', x);
            SetString(fullNetPath, nil, x);
            returnValue := WNetGetconnection(PChar(driveLetter), PChar(fullNetPath),x);
            {$ELSE}
            returnValue := WNetGetconnection(@DriveLetter[1], @FullNetPath[1], @x);
            {$ENDIF}

returnValue is returning 51 here. I can't find what that means, do you have a list of return values somewhere (you knew 487)? Any ideas why the 16-bit version is not working?

Thanks a lot, Tom.

0
 

Author Comment

by:tomcorcoran
ID: 1353674
Sorry, should have mentioned that I do:

   {$IFDEF WIN32}
   x: integer;
   {$ELSE}
   x: word;
  {$ENDIF}

   {$IFDEF WIN32}
   x := 0;
   {$ELSE}
   { make the size one less than the buffer }
   x := 255;
   {$ENDIF}

0
 
LVL 3

Expert Comment

by:vladika
ID: 1353675
Code 51 (in hex $33) is WN_BAD_LOCALNAME (see WinTypes.INT)
@DriveLetter[1] is NOT NULL-terminated string !!!

So, In Delphi 1

var
  PDriveLetter, PFullNetPath: PChar;
  X: Word;

// ......... code .......
  PDriveLetter := StrAlloc(Length(DriveLetter)+1);
  try
    PDriveLetter := StrPCopy(PDriveLetter, DriveLetter);
    X := 0;
    returnValue := WNetGetConnection(PDriveLetter, nil, @X);
    if X>256 then
      raise Exception.Create('FullNetPath too long !!!');
    if X <> 0 then
    begin
      PFullNetPath := StrAlloc(X);
      try
        returnValue := WNetGetConnection(PDriveLetter, PFullNetPath, @X);
        FullNetPath := StrPas(PFullNetPath);
      finally
        StrDispose(PFullNetPath);
      end;
    end;
  finally
    StrDispose(PDriveLetter);
  end;

// .....

The main strings difference in 16-bit and 32-bit Delphi is
In 16-bit Delphi string is SHORT string
In 32-bit Delphi string is LONG string

The short string type represents a statically-allocated string with maximum length between 1 and 255 characters, and a dynamic length between 0 and the maximum length. The short string type primarily exists for reasons of backward compatibility with earlier versions of Delphi and Borland Pascal.

The long string type represents a dynamically-allocated string with a maximum length limited only by available memory.

See Help in 32-bit Delphi.

Vladika.
0
 

Author Comment

by:tomcorcoran
ID: 1353676
Vladika,

Many thanks again, I'm sure that will work. I should have seen the problame was because of the different strings. Thanks, Tom.
0

Featured Post

On Demand Webinar: Networking for the Cloud Era

Ready to improve network connectivity? Watch this webinar to learn how SD-WANs and a one-click instant connect tool can boost provisions, deployment, and management of your cloud connection.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
Have you ever had your Delphi form/application just hanging while waiting for data to load? This is the article to read if you want to learn some things about adding threads for data loading in the background. First, I'll setup a general applica…
Visualize your data even better in Access queries. Given a date and a value, this lesson shows how to compare that value with the previous value, calculate the difference, and display a circle if the value is the same, an up triangle if it increased…
How to fix incompatible JVM issue while installing Eclipse While installing Eclipse in windows, got one error like above and unable to proceed with the installation. This video describes how to successfully install Eclipse. How to solve incompa…
Suggested Courses

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question